Overview of UCLA Research Activities on Overview of UCLA Research Activities on

Fusion Nuclear Science and TechnologyFusion Nuclear Science and Technology

Briefing to Professor Osamu Motojima and Japanese delegation from NIFS and MEXT

Signing Ceremony for Agreement onScientific Exchange and Cooperation

between Japan (NIFS) and UCLA (HSSEAS and CESTAR)

Mohamed Abdou

November 28, 2006

UCLA Activities in Fusion Nuclear Science and Technology

• US ITER Test Blanket Module Activity: • Technical Planning, Design, and Analysis• Modeling Development and Experimental Activities

• JUPITER-II (started April 2001)• Molten Salt Thermofluid MHD Flow Simulation • Solid Breeder/SiC Material System Thermomechanics

• Solid breeder blanket research activates under IEA Collaboration

• Tritium permeation and control • Interface thermal conductance

• ITER Basic Machine and US Procurement Package Support

• Free Surface Liquid Metal MHD Experiments and Modeling for Liquid Divertors and Melt Layers

• Z-pinch Vapor Recombination Dynamics Study

US ITER TBM

UCLA Leadership in the Development of the US TBM Technical Plan and Cost Estimate

• A proposed technical plan for US ITER TBM has been developed over the past 1.5 years.

• An external review of US DOE technical and project experts found the cost and plan “complete and credible” and “ready to be implemented”

• The cost averages between $5M to $10M per year over the next 10 yrs for all the R&D, Design, Fabrication and Testing needed for the US H-H Phase TBMs and supporting systems.

– The exact amount depends on the level of international collaboration and degree of integration among ITER Parties

– A significant fraction of the manpower, facilities, codes and other important resources already exist in the base program

UCLA Plays a Lead Role on US-TBM

US ITER TBM

DCLL TBM Module (1660 x 484 x 410 mm)

He-cooled RAFS FW

Poloidal flowPbLi Channel

SiC FCI

HCCB TBM sub-module (710 389 510 mm)

He-cooled RAFS FW

Ceramic breeder pebbles

Be Pebbles

Proposed US baseline strategy proposes Proposed US baseline strategy proposes different levels of participation for two US different levels of participation for two US TBM concepts – official US program under TBM concepts – official US program under consideration at DOEconsideration at DOE

UCLA Roles:UCLA Roles:• US solid breeder TBM scaling, US solid breeder TBM scaling,

test module designtest module design• US DCLL thermofluid MHD US DCLL thermofluid MHD

experiments and simulationsexperiments and simulations• US TBWG representationUS TBWG representation

HCCB Joint Partnership

The proposed US HCCB sub-module will occupy 1/3 of an ITER horizontal half-port

The back plate coolant supply and collection manifold assembly, incorporating various penetration pipes, flexible supports, and keyways, should be collaboratively designed by partner Parties.

KO Submodule

JA Submodule

US Submodule

Preliminary discussions occurred among US, Japan, and Korea about a possible partnership on HCCB.

US ITER TBM

UCLA MHD group is one of the world’s key teams working in the area of fusion LM MHD

DCLL DEMO BLANKET

B-field

Blanket performance is strongly affected by MHD phenomena

UCLA group performs MHD studies under DCLL blanket conditions for both DEMO blanket and ITER TBM.

Strategy encompasses:• Full 3D simulation tool

development• Models for specific

phenomena (e.g. natural convection, MHD turbulence)

• Key EXPERIMENTS to validate/improve simulations and understanding

FCI

He

PbLi

Flow Channel Insert isthe key element of theDCLL concept, servingas electric and thermalinsulator

UCLA is collaborating on HIMAG 3D - a complex geometry simulation code for Closed and Open Channel MHD flows

Simulations are crucial to both understanding phenomena and exploring possible flow options for DCLL and FCIs, and NSTX Li module

Problem is challenging from a number of physics and computational aspects requiring clever formulation and numerical implementation

Consistent and conservative scheme developed to conduct the simulation of MHD with high accuracy at high Hartmann numbers

Pipe flow on unstructured grid in strong field gradient – good match to experimental data at high HaBmax = 2.08 T, Ha = 6640

N = 11061, Re = 3986U = 0.07 m/s

Model development focuses on key MHD phenomena that affect thermal performance via

modification of the MHD velocity field A. Formation of high-

velocity near-wall jets

B. 2-D MHD turbulence in flows with M-type velocity profile

C. Reduction of turbulence via Joule dissipation

D. Natural/mixed convection changes flow field dramatically

E. Strong effects of MHD flows and FCI properties on heat transfer

-0.15 -0.1 -0.05 0 0.05 0.1 0.15R adia l d istance, m

400

800

1200

1600

Tem

pera

ture

, C

lam inar flow m odelturbulent flow m odel

DEMO

E g

D

B

=500

=100

=5

A C

VTBM - VTBM - Integrated Data/multi-code multi-physics modeling Integrated Data/multi-code multi-physics modeling activities, or Virtual TBM, is key for ITER TBM R&D activity.activities, or Virtual TBM, is key for ITER TBM R&D activity.

CAD Model Input

CAD to Analysis Intermediaries

Fix CAD model

Neutronics Electromagnetics

Thermo Fluid

Mass Transfer Structural

US ITER TBM• The design of a complex system like the ITER TBM requires an exhaustive CAE effort encompassing multiple simulation codes supporting multi-physics modeling.

The ferritic structural box with the first wall helium coolant channels for the HCCB TBM. (CAD model from SolidWorks)

Temperature field from Thermo-Fluid Analysis using SC/Tetra

Deformation (Thermal expansion) field from structural analysis using ANSYS

UCLA Facilities and Capabilities Utilized in JUPITER-II Collaboration on Flibe Thermofluid

MHD Research with Japanese Universities

UCLA MTOR MHD Facility

BOB magnet

Test section lit by pulsed YAG laser during Particle Image Velocimetry measurements

JUPITER 2 MHD Heat Transfer Exp. in UCLA FLIHY Electrolyte Loop

0 0.01 0.02

0.5

0.6

0.7

0.8

0.9

1

interaction parameter Ha2/Re

Nu

M/N

u

Present result 30%KOH, circular pipe Gardner (1970) mercury, circular pipe Blum (1967) 15% KOH, square duct flow

NuM=Nu(1-3Ha2/Re)

JUPITER-II Key Result - Strong MHD effect on turbulenceseen, even at low Ha typical of low conductivity Flibe

10-1 1 10 1020

20

40

60

80Re=9000

Ha=0 (St=0) Ha=5 (St=0.003) Ha=10(St=0.01) Kader

y+

T+

Ha = 0

Ha = 20

velocity fluctuations severely reduced…

Re = 5400

Near wall temperature increases…

and global Nu number decreases…

JUPITER-II SiCf/SiC Breeder Pebble Bed Thermomechanics Interaction Study

with Keyence High Precision Laser position system for displacement measurement

A constant force of 4 N is applied to each bolt during the course of the experiment.

-400

0

400

800

1200

1600

0 200 400 600 800 1000

Temperature (C)

Dis

pla

cem

ent

(um

)

Themex 1

Themex 1 Cooling

Themex 2

Themex 2 Cooling

Themex 3

Themex 3 Cooling

CEA Li2TiO3 pebbles/ CVD SiC clad

Li4SiO4/Li2O pebble bed

SiC plate

Capacitance displacement sensor

Port available for laser displacement sensors

Kovar

SS-316

Deformation/Stress/Creep Data were used in conjunction with UCLA were used in conjunction with UCLA DEM simulation code to develop DEM simulation code to develop temperature dependent stress/strain temperature dependent stress/strain constitutive correlations – constitutive correlations – vital for vital for accurate finite element analysisaccurate finite element analysis

UCLA Research on Liquid Metal Free Surface MHD for Liquid Divertor: Modeling & Experiments

Experiments on film flows show turbulent fluctuations organize into 2D structures with vorticity along the magnetic field

‘Pinching in’ seen in HIMAG simulations and experiments

• The use of fast flowing lithium films as divertor target will lead to considerable improvement in plasma performance by gettering of impurities, allowing low recycling operation and handling of the high heat loads.

• A good understanding of the dynamics of fast flowing liquid metal streams under spatially varying three component magnetic fields has to be established.

The free surface structure is affected by the magnetic field, thus influencing its transport properties governing the heat and mass transfer.

Flow can ‘Pinch-IN’ in field gradients and separate from the wall. This phenomenon is observed in experiments and numerical modeling, creating undesireable ‘bare spots’

‘Pinching in’

Flow

Divertor design for NSTX

A novel double pulse spectroscopic diagnostic was developed at UCLA to evaluate the feasibility of separating

the Z-Pinch RTL material from the molten flibe

Conceptual Z-pinch power plant

Fiber Optics

Z-boxHiCAT

0.25 m DualMonochrometer

0.25 m DualMonochrometer

Ignitron2[kV]

C=55[F]C=55[F]

Capacitor Bank (5[kJ] Max)

SCRtriggercircuit

1 2

1 2

Spectrometer

0

0.5

1

1.5

2

2.5

3

0.0E+00 5.0E-05 1.0E-04 1.5E-04 2.0E-04

time [sec]

curr

en

t [kA

]

1st pulse (high energy) used to produce and excite/ionize Fe & salt vapor

2nd pulse (low energy)used to re-excite Fe, Na after a time delay of 140-300 s

Double pulse spectroscopy

Initial results suggested that effective means of separating either metal halides or precipitated metal (after hydro-fluoridation) from liquid flibe will need to be investigated for Z-IFE.

UCLA Activities in Fusion Nuclear Science and Technology

• US ITER Test Blanket Module Activity: • Technical Planning, Design, and Analysis• Modeling Development and Experimental Activities

• JUPITER-II (started April 2001)• Molten Salt Thermofluid MHD Flow Simulation • Solid Breeder/SiC Material System Thermomechanics

• Solid breeder blanket research activates under IEA Collaboration

• Tritium permeation and control • Interface thermal conductance

• ITER Basic Machine and US Procurement Package Support

• Free Surface Liquid Metal MHD Experiments and Modeling for Liquid Divertors and Melt Layers

• Z-pinch Vapor Recombination Dynamics Study